Electromagnetic wave guide systems



ELECTROMAGNETIC WAVE GUIDE SYSTEMS Filed May 29, 1952 n= Any integer \=Operating wavelength Inventor A. W- GENT- R.T. LAWRENCE @mfl oh. 02%

Attorney United States Patent 2,736,863 ELECTROMAGNETIC WAVE GUIDE SYSTEMS Alfred Walter Gent and Ralph Thomas Lawrence, London, England, assignors to International Standard Electric Corporation, New York, N. Y.

Application May 29, 1952, erial No. 290,782

Claims priority, application Great Britain luly 13, N51

2 Claims. (Cl. 333--9) This invention relates to electromagnetic wave-guide systems of the kind in which a single wire with or without a thin dielectric covering is used for the transmission of very high frequencies.

Such a wave-guide has been called a G-line. Information on G-lines will be found in an article by G. Goubau in the Journal of Applied Physics, November 1950, page 1119.

One method already proposed for coupling to a G-line is to supply the waves from a coaxial cable, the central conductor of which is connected collinearly to the G-line, the outer conductor at the open end being flared out into a horn coaxial with the G-line.

According to the present invention, the central condoctor of the coaxial line emerges from the open end thereof perpendicularly to the G-line and is soldered or otherwise electrically connected thereto, and extends beyond the G-line for a distance equal to an odd multiple of half the operating wavelength.

The arrangement is illustrated in the figure of the accompanying drawing.

The inner conductor 1 of the coaxial cable emerges from the open end of the outer conductor 2 at right angles to the G-line 3. A joint is made at 4, and the inner conductor continues beyond the G-line for a distance equal to an odd multiple of half the operating Wavelength x, the extension being designated 5. The joint 4 may be made by soldering or welding, or simply by tying the conductors together with binding wire.

With this arrangement the waves will be propagated "ice in both directions along the G-line 3. If it is desired to transmit the waves in one direction only, a wire stub 6 may be attached perpendicularly to the G-line at a distance of an odd number of quarter wavelengths from the joint 4. The stub 6 should be an odd number of quarter Wavelengths long; in practice, no particular advantage will be gained by making it more than one quarter wavelength long, or by making the extension 5 more than one half wavelength long. The stub 6 acts as a reflector and prevents the transmission of the Waves in the right-hand direction along the G-line.

It will be understood that if transmission in both directions is desired, the stub 6 should be omitted.

The coupling arrangement described may be used for transferring the waves in either direction between the G-line and the coaxial line.

While the principles of the invention have been described above in connection with specific embodiments, and particular modifications thereof, it is to be clearly understood that this description is made by way of example and not as a limitation on the scope of the invention.

What we claim is:

1. An arrangement for transferring high frequency waves between a coaxial line having outer and inner conductors and a single conductor transmission line, comprising an extension of said inner conductor from an open end of said coaxial line and extending at right angles to said transmission line, the inner conductor continuing beyond said transmission line a distance equal to an odd number of half wavelengths of said high frequency wave, and coupled thereto at the point of crossover.

2. An arrangement according to claim 1 and further comprising a wire stub coupled perpendicularly to the transmission line at a distance of an odd number of quarter wavelengths of the said high frequency waves from the junction between the inner conductor and said transmission line, the length of the said stub being equal to an odd number of quarter Wavelengths of the said high frequency waves.

References Cited in the file of this patent Publication I, I ournal of Applied Physics, November 1950, vol. 21, No. 11, pages 1119-1128. 

